AriPerkkio
@ariperkkio.dev
@vitest.dev Core Team • Open Source at @stackblitz.com • github.com/AriPerkkio
Reposted by AriPerkkio
⚡ ever wanted to download @stackblitz.com projects without opening the site?
you now can 🎉
🌐 web: replace stackblitz.com w/ stackblitz.zip in any edit url
🖥️ cli: `npx stackblitz-zip` or `npx stackblitz-clone `
📦 npm: `npm i stackblitz-zip`
built for myself to grab repros from issues
you now can 🎉
🌐 web: replace stackblitz.com w/ stackblitz.zip in any edit url
🖥️ cli: `npx stackblitz-zip
📦 npm: `npm i stackblitz-zip`
built for myself to grab repros from issues
November 12, 2025 at 5:15 PM
⚡ ever wanted to download @stackblitz.com projects without opening the site?
you now can 🎉
🌐 web: replace stackblitz.com w/ stackblitz.zip in any edit url
🖥️ cli: `npx stackblitz-zip` or `npx stackblitz-clone `
📦 npm: `npm i stackblitz-zip`
built for myself to grab repros from issues
you now can 🎉
🌐 web: replace stackblitz.com w/ stackblitz.zip in any edit url
🖥️ cli: `npx stackblitz-zip
📦 npm: `npm i stackblitz-zip`
built for myself to grab repros from issues
Excited to see Typesafe CSF factories solve RFC I wrote two years ago. No more explicit TS typings! github.com/storybookjs/...
November 5, 2025 at 6:52 AM
Excited to see Typesafe CSF factories solve RFC I wrote two years ago. No more explicit TS typings! github.com/storybookjs/...
Reposted by AriPerkkio
My talk slides are available here hiroshi-talks.vercel.app/2025-10-25/1 also with source code in github.com/hi-ogawa/talks It was a great experience to talk with many awesome folks in person! Thanks @vuefes.bsky.social for the opportunity!
October 27, 2025 at 9:18 AM
My talk slides are available here hiroshi-talks.vercel.app/2025-10-25/1 also with source code in github.com/hi-ogawa/talks It was a great experience to talk with many awesome folks in person! Thanks @vuefes.bsky.social for the opportunity!
Reposted by AriPerkkio
Vitest 4 is out!
- Browser Mode is Stable
- Visual Regression Testing
- Improved Debugging
- Pool Stabilization
- New APIs
- Bug Fixes
Stay updated with our blog post:
vitest.dev/blog/vitest-4
- Browser Mode is Stable
- Visual Regression Testing
- Improved Debugging
- Pool Stabilization
- New APIs
- Bug Fixes
Stay updated with our blog post:
vitest.dev/blog/vitest-4
Announcing Vitest 4.0
Vitest 4.0 Release Announcement
vitest.dev
October 22, 2025 at 3:43 PM
Vitest 4 is out!
- Browser Mode is Stable
- Visual Regression Testing
- Improved Debugging
- Pool Stabilization
- New APIs
- Bug Fixes
Stay updated with our blog post:
vitest.dev/blog/vitest-4
- Browser Mode is Stable
- Visual Regression Testing
- Improved Debugging
- Pool Stabilization
- New APIs
- Bug Fixes
Stay updated with our blog post:
vitest.dev/blog/vitest-4
After maintaining Tinypool for over 2 years I'm happy to see next version of Vitest dropping it. I've written some reasoning about this in the linked PR. Even though this change is significant for Vitest, I'm more confident about it than making new changes in Tinypool.
github.com/vitest-dev/v...
github.com/vitest-dev/v...
feat!: rewrite pools without `tinypool` by AriPerkkio · Pull Request #8705 · vitest-dev/vitest
Description
Removes Tinypool and adds new custom internal pool for Vitest only. Some previous thoughts I wrote ~2 months ago about this below.
Vitest uses tinypool for orchestrating how test file...
github.com
October 21, 2025 at 5:47 PM
After maintaining Tinypool for over 2 years I'm happy to see next version of Vitest dropping it. I've written some reasoning about this in the linked PR. Even though this change is significant for Vitest, I'm more confident about it than making new changes in Tinypool.
github.com/vitest-dev/v...
github.com/vitest-dev/v...
Reposted by AriPerkkio
VoidZero's @erus.dev talks about the upcoming @vitest.dev features including the new report API and multi-browser configuration as well as what to expect in Vitest 4
🧪 Full video in comments
🧪 Full video in comments
October 20, 2025 at 2:31 AM
VoidZero's @erus.dev talks about the upcoming @vitest.dev features including the new report API and multi-browser configuration as well as what to expect in Vitest 4
🧪 Full video in comments
🧪 Full video in comments
Reposted by AriPerkkio
Watch VoidZero’s @overlookmotel.bsky.social explain how oxlint tackles JS-Rust interoperability to maintain high performance for plugins.
Full video in comment 👇
Full video in comment 👇
October 14, 2025 at 9:18 AM
Watch VoidZero’s @overlookmotel.bsky.social explain how oxlint tackles JS-Rust interoperability to maintain high performance for plugins.
Full video in comment 👇
Full video in comment 👇
Setting custom `process.title` in Node takes around 10-20ms. Vitest used to do this for every isolated test file so that debugging test runner processes was a bit nicer experience. But it's not worth the performance hit.
August 28, 2025 at 7:49 AM
Setting custom `process.title` in Node takes around 10-20ms. Vitest used to do this for every isolated test file so that debugging test runner processes was a bit nicer experience. But it's not worth the performance hit.
Reposted by AriPerkkio
Published a post I started writing half a year ago. Make sure to use the latest versions of each build tools and configure the settings appropriately!
green.sapphi.red/blog/address...
green.sapphi.red/blog/address...
Addressing Source Code Leaks Across the Ecosystem – A Retrospective
green.sapphi.red
August 2, 2025 at 8:08 AM
Published a post I started writing half a year ago. Make sure to use the latest versions of each build tools and configure the settings appropriately!
green.sapphi.red/blog/address...
green.sapphi.red/blog/address...
Reposted by AriPerkkio
Our latest post walks through how to use the coverage reporting in Storybook 9 to be sure your components are well-tested.
Frontend test coverage with Storybook 9
Stories give you free test coverage
storybook.js.org
June 18, 2025 at 6:38 PM
Our latest post walks through how to use the coverage reporting in Storybook 9 to be sure your components are well-tested.
We've added new coverage provider comparison page on Vitest documentation. This guide describes the lower level differences between Istanbul and V8. It should help users choosing which provider to use. vitest.dev/guide/covera...
June 6, 2025 at 7:40 AM
We've added new coverage provider comparison page on Vitest documentation. This guide describes the lower level differences between Istanbul and V8. It should help users choosing which provider to use. vitest.dev/guide/covera...
AST based V8 code coverage is finally here! I thought of this feature first time over 2 years ago, but knew it would require so much work that I couldn't finish it by working on Vitest just on weekends. Ever since @stackblitz.com hired me to work on Vitest I knew I could finish features like this.
Vitest 3.2 is out!
- New Annotations API
- Scoped Fixtures
- Custom Browser Locators API
- Test Signal
- Better V8 Coverage Result
And many more features!
vitest.dev/blog/vitest-...
- New Annotations API
- Scoped Fixtures
- Custom Browser Locators API
- Test Signal
- Better V8 Coverage Result
And many more features!
vitest.dev/blog/vitest-...
June 2, 2025 at 5:37 PM
AST based V8 code coverage is finally here! I thought of this feature first time over 2 years ago, but knew it would require so much work that I couldn't finish it by working on Vitest just on weekends. Ever since @stackblitz.com hired me to work on Vitest I knew I could finish features like this.
Reposted by AriPerkkio
Vitest 3.2 is out!
- New Annotations API
- Scoped Fixtures
- Custom Browser Locators API
- Test Signal
- Better V8 Coverage Result
And many more features!
vitest.dev/blog/vitest-...
- New Annotations API
- Scoped Fixtures
- Custom Browser Locators API
- Test Signal
- Better V8 Coverage Result
And many more features!
vitest.dev/blog/vitest-...
June 2, 2025 at 2:11 PM
Vitest 3.2 is out!
- New Annotations API
- Scoped Fixtures
- Custom Browser Locators API
- Test Signal
- Better V8 Coverage Result
And many more features!
vitest.dev/blog/vitest-...
- New Annotations API
- Scoped Fixtures
- Custom Browser Locators API
- Test Signal
- Better V8 Coverage Result
And many more features!
vitest.dev/blog/vitest-...
Onboarding on new @storybook.js.org projects is just perfect. So nice to have testing setup *covered* out-of-the-box. 🤝
May 21, 2025 at 8:30 AM
Onboarding on new @storybook.js.org projects is just perfect. So nice to have testing setup *covered* out-of-the-box. 🤝
Reposted by AriPerkkio
@bolt.new are looking for an engineer to advance web computing by working on WebContainer, the first in-browser WebAssembly-based operating system.
You'd be getting paid to be an Open Source contributor, AND you'd get to work with @patak.dev. Sounds pretty good to us!
opensourcepledge.com/jobs/
You'd be getting paid to be an Open Source contributor, AND you'd get to work with @patak.dev. Sounds pretty good to us!
opensourcepledge.com/jobs/
May 14, 2025 at 11:29 AM
@bolt.new are looking for an engineer to advance web computing by working on WebContainer, the first in-browser WebAssembly-based operating system.
You'd be getting paid to be an Open Source contributor, AND you'd get to work with @patak.dev. Sounds pretty good to us!
opensourcepledge.com/jobs/
You'd be getting paid to be an Open Source contributor, AND you'd get to work with @patak.dev. Sounds pretty good to us!
opensourcepledge.com/jobs/
After couple of days looking at *.cpuprofile's, I think it's getting closer to stable v1 release. The ~3MB checker.ts from Typescript repo is perfect benchmarking reference for tools that process source code. When generating coverage for 'vuejs/core' repo, speed is close to original v8-to-istanbul.
April 6, 2025 at 9:01 AM
After couple of days looking at *.cpuprofile's, I think it's getting closer to stable v1 release. The ~3MB checker.ts from Typescript repo is perfect benchmarking reference for tools that process source code. When generating coverage for 'vuejs/core' repo, speed is close to original v8-to-istanbul.
This release includes long-awaited "--silent=passed-only" option, that can be used to hide console.log calls from passing tests. Only the logs from failing tests are reported.
March 31, 2025 at 1:46 PM
This release includes long-awaited "--silent=passed-only" option, that can be used to hide console.log calls from passing tests. Only the logs from failing tests are reported.
Finalizing rewrite of AST-aware v8-to-istanbul. This will provide accuracy of Istanbul coverage for V8 coverage reports. I've intentionally kept this tool unopinionated so that it's not strictly tied to just @vitest.dev - it should be usable with Jest, C8, Playwright and node:test too.
March 21, 2025 at 9:42 AM
Finalizing rewrite of AST-aware v8-to-istanbul. This will provide accuracy of Istanbul coverage for V8 coverage reports. I've intentionally kept this tool unopinionated so that it's not strictly tied to just @vitest.dev - it should be usable with Jest, C8, Playwright and node:test too.
Reposted by AriPerkkio
We are proud to announce the First Ever ViteConf taking place in person 🤩
Join the Creator of Vite, @evanyou.me, Core Team, Ecosystem Authors and Experts!
📍 10 October, Amsterdam
👋 Sign up for the waiting list to be notified about the ticket release via viteconf.org
Join the Creator of Vite, @evanyou.me, Core Team, Ecosystem Authors and Experts!
📍 10 October, Amsterdam
👋 Sign up for the waiting list to be notified about the ticket release via viteconf.org
March 15, 2025 at 6:04 PM
We are proud to announce the First Ever ViteConf taking place in person 🤩
Join the Creator of Vite, @evanyou.me, Core Team, Ecosystem Authors and Experts!
📍 10 October, Amsterdam
👋 Sign up for the waiting list to be notified about the ticket release via viteconf.org
Join the Creator of Vite, @evanyou.me, Core Team, Ecosystem Authors and Experts!
📍 10 October, Amsterdam
👋 Sign up for the waiting list to be notified about the ticket release via viteconf.org
Reposted by AriPerkkio
Huge improvement for Vitest development workflow, thanks to isolated declaration! I didn't think the migration was possible until I see PRs by @sxzz.dev. Just started to sponsor Kevin for the amazing work!
March 9, 2025 at 6:23 AM
Huge improvement for Vitest development workflow, thanks to isolated declaration! I didn't think the migration was possible until I see PRs by @sxzz.dev. Just started to sponsor Kevin for the amazing work!
Tree-view of @vitest.dev verbose reporter is coming back! We (well I did) forgot to implement this during v3's reporter rewrites. I had already forgot how good it looks.
February 16, 2025 at 1:52 PM
Tree-view of @vitest.dev verbose reporter is coming back! We (well I did) forgot to implement this during v3's reporter rewrites. I had already forgot how good it looks.
Reposted by AriPerkkio
In 2025, we’re doubling down on our support to Open Source.
We’re thrilled to announce the Bolt 100K Open Source Fund:
We’re thrilled to announce the Bolt 100K Open Source Fund:
Bolt 100K Open Source Fund
We're doubling down on our support to Open Source in 2025 with a 100K fund targeted at web infrastructure and Bolt dependencies.
blog.stackblitz.com
February 13, 2025 at 6:08 PM
In 2025, we’re doubling down on our support to Open Source.
We’re thrilled to announce the Bolt 100K Open Source Fund:
We’re thrilled to announce the Bolt 100K Open Source Fund:
Reposted by AriPerkkio
🤏 it's a good day for tinypool!
thank you so much @sebastienlorber.com and @ariperkkio.dev ❤️
github.com/facebook/doc...
thank you so much @sebastienlorber.com and @ariperkkio.dev ❤️
github.com/facebook/doc...
feat(core): Docusaurus Faster - SSG worker threads by slorber · Pull Request #10826 · facebook/docusaurus
Motivation
This PR introduces a new Docusaurus Faster option: siteConfig.future.experimental_faster.ssgWorkerThreads.
It permits you to optimize the static site generation phase of your site, by ex...
github.com
February 8, 2025 at 1:28 PM
🤏 it's a good day for tinypool!
thank you so much @sebastienlorber.com and @ariperkkio.dev ❤️
github.com/facebook/doc...
thank you so much @sebastienlorber.com and @ariperkkio.dev ❤️
github.com/facebook/doc...
Huge thanks to @sapphi.red for helping the @vitest.dev team with these findings. Perfect collaboration between projects. 🤝
We've released patches for a critical security vulnerability. We strongly encourage projects to upgrade to versions 1.6.1, 2.1.9, or 3.0.5 as soon as possible.
Remote Code Execution when accessing a malicious website while Vitest API server is listening
### Summary
Arbitrary remote Code Execution when accessing a malicious website while Vitest API server is listening by Cross-site WebSocket hijacking (CSWSH) attacks.
### Details
When [`api` o...
github.com
February 4, 2025 at 8:34 AM
Huge thanks to @sapphi.red for helping the @vitest.dev team with these findings. Perfect collaboration between projects. 🤝